Probably the weirdest AND most ambitious Doom mod out there. Through clever spawning scripts, it randomly replaces all enemies and items in any given level (almost all maps supported) with equivalent but randomly chosen items from the history of the FPS genre. A shotgun zombie may be replaced by a crazy old coot from Redneck Rampage, or an uzi-toting demon ninja from Shadow Warrior, for instance. Perhaps even 2d-ified versions of Quake and Quake 2 enemies! There are hundreds of enemy types, and almost as many weapons. It's relatively well balanced, though, and is in active development.